Hey there,
Yes - Narita Airport is the main international airport of Tokyo (so I assumed that was where you're landing). If you arrive at Haneda airport, then the cost from the airport will be around ¥500 each way.
I don't think this would really affect the decision about a 14 day pass. You'll need to spend ¥17,690 more on JR travel in addition to your itinerary to make a 14 day pass worth it (could be made up in a return to Hiroshima or Takayama from Nagoya for example).
The Nationwide Japan Rail Pass (which is what you will need for the area you intend to cover) is only available for purchase outside of Japan. You can not purchase it in Japan.
aaaand last of all, the Nozomi from Tokyo to Nagoya is ¥10,980 one way.
Hope this helps!